1. Field of the Invention
The invention relates to a device for detecting suspicious objects, the device includes a radiation tunnel in which an x-ray source and a detector unit are disposed, whose detectors for detecting transmitted radiation are directed toward the x-ray source.
2. Description of the Background Art
As is generally known, scanners, which generate a transmission image of the object to be examined with use of x-rays, are employed as devices for detecting suspicious objects. In so doing, the x-rays not absorbed by the examined object are detected by a detector unit.
In prior-art inspection systems, for example, those described in DE 101 31 407-A, which corresponds to U.S. Pat. No. 6,663,280, which is incorporated herein by reference, and in which a suitably designed conveyor belt moves the items of luggage to be inspected through the radiation tunnel, in which one or more radiation sources and detector units directed toward them are disposed.
The use of known devices for screening persons, for example, flight passengers, for suspicious objects, however, is associated with the following disadvantages:
In order to reach the conveyor belt, the person to be screened must climb over a step. Although the height difference to be overcome can be kept small by a suitable design of the device, it poses difficulties particularly for elderly or disabled persons.
At the start-up of the conveyor belt for the screening and during braking following the screening, individuals are exposed to acceleration forces. The acceleration forces can in fact be reduced by an appropriate conveyor belt operating mode, but pose problems particularly for individuals with physical impairments. There is the risk that individuals lose their balance.
The relative speed between the conveyor belt and the x-rays must be kept very precise to keep the x-ray dose per scan interval at the desired low values. The precise maintenance of the relative speed can be detrimentally affected by disruptive factors such as soiling of the belt or a change in belt speed caused by the different weight of individuals or by shifts in weight such as movements by individuals.